Fixture Unit Calculator
Count drainage and water supply fixture units (DFU/WSFU) to size drain and supply lines per plumbing code.
Flush valve = 4 DFU, tank type = 4 DFU per IPC Table 709.1
Bathroom sinks — 1 DFU each
With or without shower — 2 DFU each
Standalone showers — 2 DFU each
Residential kitchen sink — 2 DFU each
Residential dishwasher — 2 DFU each
Standard residential washer — 2 DFU each
Floor drains — 1 DFU each, no supply units
Outdoor faucets — supply only (2.5 WSFU), no drain units
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